Benefits and Limitations of DNA Barcoding and Metabarcoding in Herbal Product Authentication

Biological Ingredient Analysis of Traditional Herbal Patent Medicine Fuke Desheng Wan Using the Shotgun Metabarcoding Approach

With the widespread use of traditional medicine around the world, the safety and efficacy of traditional herbal patent medicine have become an increasing concern to the public. However, it is difficult to supervise the authenticity of herbal materials in mixed herbal products according to the current quality standards, especially for traditional herbal patent medicine, with a distinct variance in the dosage of herbal materials. This study utilized the shotgun metabarcoding approach to analyze the biological ingredients of Fuke Desheng Wan (FKDSW), which is an effective traditional herbal product for the treatment of dysmenorrhea. Six herbal materials were collected, and a lab-made mock FKDSW sample was produced to establish a method for the authentication assessment of biological ingredients in traditional herbal patent medicine based on shotgun metabarcoding. Furthermore, four commercial FKDSW samples were collected to verify the practicality of the shotgun metabarcoding approach. Then, a total of 52.16 Gb raw data for 174 million paired-end reads was generated using the Illumina NovaSeq sequencing platform. Meanwhile, 228, 23, and 14 operational taxonomic units (OTUs) were obtained for the ITS2, matK, and rbcL regions, respectively, after bioinformatic analysis. Moreover, no differences were evident between the assembly sequences obtained via shotgun metabarcoding and their corresponding reference sequences of the same species obtained via Sanger sequencing, except for part of the ITS2 and matK assembly sequences of Paeonia lactiflora Pall., Saussurea costus (Falc.) Lipsch. and Bupleurum chinense DC. with 1–6 different bases. The identification results showed that all six prescribed ingredients were successfully detected and that the non-authentic ingredient of Bupleuri Radix (Chaihu, Bupleurum chinense DC. or Bupleurum scorzonerifolium Willd.) was found in all the commercial samples, namely Bupleurum falcatum L. Here, 25 weed species representing 16 genera of ten families were detected. Moreover, 26 fungal genera belonging to 17 families were found in both lab-made and commercial FKDSW samples. This study demonstrated that the shotgun metabarcoding approach could overcome the biased PCR amplification and authenticate the biological ingredients of traditional herbal patent medicine with a distinct variance in the dosage of the herbal materials. Therefore, this provides an appropriate evaluation method for improving the safety and efficacy of traditional herbal patent medicine.

DNA meta-barcoding using rbcL based mini-barcode revealed presence of unspecified plant species in Ayurvedic polyherbal formulations

INTRODUCTION

Ayurveda takes advantage of the beneficial properties of medicinal plants. High demands in combination with inadequate availability of botanicals and a lack of knowledge with respect to their precise identification lead to adulterations in herbal products. Identification becomes more difficult in complex herbal formulations. Four different polyherbal formulations have been analyzed for the present paper. The targeted plants have different pharmacological properties for various ailments.

OBJECTIVE

We aimed to examine the rbcL gene based plant DNA mini-barcode to identify target and non-target plants in polyherbal formulations by using high-throughput next generation sequencing.

METHODS

Degenerate primers of the selected mini-barcode region have been identified from the literature. A blend of 30 authentic medicinal plant species was used to examine the species resolution capacity of the mini-barcode. DNA was isolated from herbal formulations, an amplicon library was prepared, and sequencing was performed on an IonS5 system. Data were analyzed using various bioinformatics tools.

RESULTS

Analysis of control pooled samples revealed the optimum resolving power of the DNA mini-barcode. Data analysis of the commercial samples revealed that only one herbal formulation contained all plants and matched with listed contents. In two formulations, only 10 out of 21 and 11 out of 20 plants were detected, respectively. Additionally, several non-listed plants were also detected in these formulations. Two formulations contained >20% reads assigned to non-target plants. Overall, 21.98% of the reads were assigned to non-target plants.

CONCLUSION

The present study clearly demonstrated the successful application and potential of meta-barcoding in the quality control of complex herbal matrices. The results strongly suggest that this approach can be used in pharmacovigilance of processed herbal products.

Production of photochromic nanocomposite film via spray-coating of rare-earth strontium aluminate for anti-counterfeit applications

New photochromic film was developed toward the preparation of anti-counterfeiting documents utilizing inorganic/organic nanocomposite enclosing a photoluminescent inorganic pigment and a polyacrylic binder polymer. To generate a translucent film from pigment/polyacrylic nanocomposite, the phosphorescent strontium aluminum oxide pigment should be well-dispersed in the solution of the polyacrylic-based binder without agglomeration. The photochromic nanocomposite was applied efficiently onto commercial cellulose paper documents utilizing the effective and economical spray-coating technology followed with thermofixation. A homogeneous photochromic film was immobilized onto cellulose paper surface to introduce a transparent film changing to greenish-yellow upon exposure to ultraviolet light as depicted by CIE coloration measurements. The photochromic effect was monitored at lowest pigment concentration (0.25 wt%). The spray-coated paper documents exhibit two absorbance bands at 256 and 358 nm, and two fluorescence peaks at 433 and 511 nm. The morphologies of the spray-coated documents were explored. The spray-coated paper sheets showed a reversible photochromic effect without fatigue under ultraviolet irradiation. The rheology of the produced photochromic composites as well as the mechanical properties and photostability of the spray-coated documents were studied.

The Future of DNA Barcoding: Reflections from Early Career Researchers

Over the last two decades, the use of DNA barcodes has transformed our ability to identify and assess life on our planet. Both strengths and weaknesses of the method have been exemplified through thousands of peer-reviewed scientific articles. Given the novel sequencing approaches, currently capable of generating millions of reads at low cost, we reflect on the questions: What will the future bring for DNA barcoding? Will identification of species using short, standardized fragments of DNA stand the test of time? We present reflected opinions of early career biodiversity researchers in the form of a SWOT analysis and discuss answers to these questions.

DNA Metabarcoding for Quality Control of Basil, Oregano, and Paprika

Herbs and spices are some of the most vulnerable products in terms of fraud and adulteration in the food sector. Although standard analytical methods are accurate for quality control of specific lead or marker compounds, they cannot accurately assess the entire species composition of many marketed products. Complementary analytical approaches are thus often used for comprehensive screening of herbs and spices. In this study we evaluate DNA metabarcoding for the identification and authentication of 62 products, containing basil, oregano, and paprika collected from different retailers and importers in Norway. Our results show varying degrees of discrepancy between the constituent species and those listed on the product labels, despite high product authenticity. We suggest the false positives result from the sensitivity of DNA metabarcoding and filtering thresholds should be integrated into protocols to reduce false positives. Our results highlight how integrating DNA metabarcoding into the toolbox of analytical methods for quality control of fresh and/or processed plant-based food can improve product quality.

Chemical Authentication of Botanical Ingredients: A Review of Commercial Herbal Products

Chemical methods are the most important and widely used traditional plant identification techniques recommended by national and international pharmacopoeias. We have reviewed the successful use of different chemical methods for the botanical authentication of 2,386 commercial herbal products, sold in 37 countries spread over six continents. The majority of the analyzed products were reported to be authentic (73%) but more than a quarter proved to be adulterated (27%). At a national level, the number of products and the adulteration proportions varied very widely. Yet, the adulteration reported for the four countries, from which more than 100 commercial products were purchased and their botanical ingredients chemically authenticated, was 37% (United Kingdom), 31% (Italy), 27% (United States), and 21% (China). Simple or hyphenated chemical analytical techniques have identified the total absence of labeled botanical ingredients, substitution with closely related or unrelated species, the use of biological filler material, and the hidden presence of regulated, forbidden or allergenic species. Additionally, affecting the safety and efficacy of the commercial herbal products, other low quality aspects were reported: considerable variability of the labeled metabolic profile and/or phytochemical content, significant product-to-product variation of botanical ingredients or even between batches by the same manufacturer, and misleading quality and quantity label claims. Choosing an appropriate chemical technique can be the only possibility for assessing the botanical authenticity of samples which have lost their diagnostic microscopic characteristics or were processed so that DNA cannot be adequately recovered.

Developing a non-destructive metabarcoding protocol for detection of pest insects in bulk trap catches

Metabarcoding has the potential to revolutionise insect surveillance by providing high-throughput and cost-effective species identification of all specimens within mixed trap catches. Nevertheless, incorporation of metabarcoding into insect diagnostic laboratories will first require the development and evaluation of protocols that adhere to the specialised regulatory requirements of invasive species surveillance. In this study, we develop a multi-locus non-destructive metabarcoding protocol that allows sensitive detection of agricultural pests, and subsequent confirmation using traditional diagnostic techniques. We validate this protocol for the detection of tomato potato psyllid (Bactericera cockerelli) and Russian wheat aphid (Diuraphis noxia) within mock communities and field survey traps. We find that metabarcoding can reliably detect target insects within mixed community samples, including specimens that morphological identification did not initially detect, but sensitivity appears inversely related to community size and is impacted by primer biases, target loci, and sample indexing strategy. While our multi-locus approach allowed independent validation of target detection, lack of reference sequences for 18S and 12S restricted its usefulness for estimating diversity in field samples. The non-destructive DNA extraction proved invaluable for resolving inconsistencies between morphological and metabarcoding identification results, and post-extraction specimens were suitable for both morphological re-examination and DNA re-extraction for confirmatory barcoding.

HPLC-UV, Metabarcoding and Genome Skims of Botanical Dietary Supplements: A Case Study in Echinacea

The use of DNA-based methods to authenticate botanical dietary supplements has been vigorously debated for a variety of reasons. More comparisons of DNA-based and chemical methods are needed, and concordant evaluation of orthogonal approaches on the same products will provide data to better understand the strengths and weaknesses of both approaches. The overall application of DNA-based methods is already firmly integrated into a wide array of continually modernizing stand alone and complementary authentication protocols. Recently, the use of full-length chloroplast genome sequences provided enhanced discriminatory capacity for closely related species of Echinacea compared to traditional DNA barcoding approaches (matK and rbcL). Here, two next-generation sequencing approaches were used: (1) genome skimming and (2) PCR amplicon (metabarcoding). The two genetic approaches were then combined with HPLC-UV to evaluate 20 commercially available dietary supplements of Echinacea representing "finished" products. The trade-offs involved in different DNA approaches were discussed, with a focus on how DNA methods support existing, accepted chemical methods. In most of the products (19/20), HPLC-UV suggested the presence of Echinacea spp. While metabarcoding was not useful with this genus and instead only resolved 7 products to the family level, genome skimming was able to resolve to species (9) or genus (1) with the 10/20 products where it was successful. Additional ingredients that HPLC-UV was unable to identify were also found in four products along with the relative sequence proportion of the constituents. Additionally, genome skimming was able to identify one product that was a different Echinacea species entirely.

Targeted LC-MS/MS combined with multilocus DNA metabarcoding as a combinatory approach to determine the amount and the source of pyrrolizidine alkaloids contamination in popular cooking herbs, seeds, spices and leafy vegetables

Pyrrolizidine alkaloids (PAs) and their corresponding N-oxides (PANOs) are natural protoxins biosynthesised by many plant species and are responsible for occasional fatal intoxication outbreaks due to the consumption of contaminated food. However, only in rare cases has the origin of the contamination been determined. Although their presence has been studied in many matrices, occurrence data on popular widely used cooking herbs, seeds, spices and leafy vegetables is very scarce. Therefore, a systematic study on the occurrence of PA/PANOs contaminations in these popular herbal items, available on the Belgian market, was performed, by means of a validatedtargeted LC-MS/MS analysis, followed by multilocus DNA metabarcoding to track back the origin of the contamination for seven highly to moderately contaminated samples. Our results clearly indicate that 21% of the seed spices and 25% seed-based aromatic mixes contain an amount higher than 400 μg of the 30 summed targeted PAs and PANOs per kg, the value which is currently under discussion by the European member states to be set as a maximum threshold. For both the herbs and the herb-based mixes only 7% of analysed samples exceeded these levels. As a proof of concept, multilocus DNA metabarcoding was performed on six highly contaminated samples, belonging to each subtype matrix, containing high levels of heliotrine type of PA/PANOs. Each time the analysis demonstrated the presence of DNA from a plant species belonging to the plant genus Heliotropium. Moreover, a contaminated leafy vegetable sample, containing solely senecionine type PA/PANOs, contained DNA from Senecio vulgaris. Taken together, it can be stated that the proposed combinatory chemical and molecular techniques could be used to verify if a PA/PANO(s) contamination occurred in these popular cooking items and to pinpoint the origin the contamination, which is pivotal in the case of a detrimental intoxication or intoxication outbreak.

Coronavirus Disease 2019 and Herbal Therapy: Pertinent Issues Relating to Toxicity and Standardization of Phytopharmaceuticals

Coronavirus disease 2019 (COVID-19) is a virulent viral disease that has now become a public health emergency of global significance and still without an approved treatment regimen or cure. In the absence of curative drugs and with vaccines development still in progress, alternative approaches to stem the tide of the pandemic are being considered. The potential of a phytotherapeutic approach in the management of the dreaded disease has gained attention, especially in developing countries, with several claims of the development of anti-COVID-19 herbal formulations. This is a plausible approach especially with the increasing acceptance of herbal medicine in both alternative and orthodox medical practices worldwide. Also, the established efficacy of herbal remedies in the treatment of numerous viral diseases including those caused by coronaviruses, as well as diseases with symptoms associated with COVID-19, presents a valid case for serious consideration of herbal medicine in the treatment of COVID-19. However, there are legitimate concerns and daunting challenges with the use of herbs and herbal products. These include issues of quality control, unethical production practice, inadequate information on the composition, use and mechanisms, weak regulatory policies, herb-drug interactions and adverse reactions, and the tendency for abuse. This review discusses the feasibility of intervention with herbal medicine in the COVID-19 pandemic and the need to take proactive measures to protect public health by improving the quality and safety of herbal medicine deployed to combat the disease. Graphical abstract.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43450-021-00132-x.

The efficacy of machine learning algorithm for raw drug authentication in Coscinium fenestratum (Gaertn.) Colebr. employing a DNA barcode database

Medicinal plants are a valuable resource for traditional as well as modern medicine. Consequently huge demand has exerted a heavy strain on the existing natural resources. Due to over exploitation and unscientific collection most of the commercially traded ayurvedic plants are in the phase of depletion. Adulteration of expensive raw drugs with inferior taxa has become a common practice to meet the annual demand of the ayurvedic industry. Although there are several recommended methods for proper identification varying from the traditional taxonomic to organoleptic and physiochemical, it is difficult to authenticate ayurvedic raw drugs available in extremely dried, powdered or shredded forms. In this regard, the study addresses proper authentication and illicit trade in Coscinium fenestratum (Gaertn.) Colebr. using CBOL recommended standard barcode regions viz. nuclear ribosomal-Internally Transcribed Spacer (nrDNA- ITS), maturase K (matK), ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL), and psbA-trnH spacer regions. Further, an integrated analytical approach employing Maximum Likelihood phylogenetic tree and Machine Learning Approach, Waikato Environment for Knowledge Analysis was employed to prove efficacy of the method. The automated species identification technique, Artificial Intelligence uses the ability of computers to build models that can receive the input data and then conduct statistical analyses which significantly reduces the human labour. Concurrently, scientific management, restoration, cultivation and conservation measures should be given utmost priority to reduce the depletion of wild resources as well as to meet the rapidly increasing demand of the herbal industries.

Evaluation of the trnK-matK-trnK, ycf3, and accD-psal chloroplast regions to differentiate crop type and biogeographical origin of Cannabis sativa

Cannabis sativa (marijuana and hemp) is one of the most controversial crops worldwide. In the USA, the state-specific legalization of marijuana and recently legalized hemp pose a problem for law enforcement. This study seeks to utilize chloroplast hSTRs, INDEL, and SNPs markers to develop genotyping methods to aid in the differentiation of legal hemp from illicit marijuana and also for tracking the flow of trafficked marijuana. Three polymorphic regions: trnK-matK-trnK, ycf3, and accD-psal, of the C. sativa chloroplast genome were evaluated in order to distinguish crop type and biogeographic origin. A total of nine polymorphic sites were genotyped from five distinct populations (hemp from the USA and Canada, marijuana from Chile and USA-Mexico, and medical marijuana from Chile) with a custom fragment and SNaPshot^TM assay. The study also combined genotype results from the same sample set using 21 additional polymorphic markers from previous studies. The effectiveness of these multi-locus assays to distinguish sample groups was assessed using haplotype analysis, phylogenetic analysis, pairwise comparisons, and principal component analysis. Results indicated a clear separation of Canadian hemp using only the nine polymorphic sites developed in this study. The additional 21 markers were able to separate US hemp from both marijuana groups to a significant level (p < 0.05) when assessing average Fixation Indices (F_ST). This study demonstrated the applicability of these organelle markers for the determination of crop type and biogeographic origin of C. sativa. However, a more extensive database is needed to evaluate the true discriminatory power of these markers.

Progress in the use of DNA barcodes in the identification and classification of medicinal plants

DNA barcoding is an emerging molecular identification and classification technology that has been applied to medicinal plants since 2008. The application of this technique has greatly ensured the safety and effectiveness of medicinal materials. In this paper, we review the application of DNA barcoding and some related technologies over the past 10 years with respect to improving our knowledge of medicinal plant identification and authentication. From single locus-based DNA barcodes to combined markers to genome-scale levels, DNA barcodes contribute more and more genetic information. At the same time, other technologies, such as high-resolution melting (HRM), have been combined with DNA barcoding. With the development of next-generation sequencing (NGS), metabarcoding technology has also been shown to identify species in mixed samples successfully. As a widely used and effective tool, DNA barcoding will become more useful over time in the field of medicinal plants.

Quantitative NMR Methodology for the Authentication of Roasted Coffee and Prediction of Blends

In response to the need from the food industry for new analytical solutions, a fit-for-purpose quantitative ¹H NMR methodology was developed to authenticate pure coffee (100% arabica or robusta) as well as predict the percentage of robusta in blends through the study of 292 roasted coffee samples in triplicate. Methanol was chosen as the extraction solvent, which led to the quantitation of 12 coffee constituents: caffeine, trigonelline, 3- and 5-caffeoylquinic acid, lipids, cafestol, nicotinic acid, N-methylpyridinium, formic acid, acetic acid, kahweol, and 16-O-methylcafestol. To overcome the chemical complexity of the methanolic extract, quantitative analysis was performed using a combination of traditional integration and spectral deconvolution methods. As a result, the proposed methodology provides a systematic methodology and a linear regression model to support the classification of known and unknown roasted coffees and their blends.

Risk assessment regarding the use of Annona muricata in food supplements

The current risk assessment was performed in the context of the European Food Risk Assessment Fellowship Programme (EU-FORA) supported by EFSA and was intended to evaluate possible health risks associated with the consumption of Annona muricata L. (Annonaceae) and derived food supplements. A. muricata grows as a tree and is native to the Caribbean and Central America. Preparations made from different plant parts of A. muricata (i.e. fruit, leaves, bark, roots) have been used as herbal medicine and are also marketed worldwide as over-the-counter food supplements that have been purported to support general health or to treat a wide range of health conditions, particularly cancer and parasitic infections. However, open questions remain regarding the safety of A. muricata-based food supplements, since Annonaceae have been reported to contain potentially neurotoxic compounds, i.e. acetogenins. The assessment conducted within the present fellowship programme shows that substantial uncertainties exist regarding the safe use of A. muricata-based supplements. The available data provide indications of neurotoxic potential of certain A. muricata preparations. The paucity of adequate studies, particularly related to long-term use of A. muricata supplements, currently does not allow the establishment of a safe intake level. Within this technical report a workflow of the project is presented.

DNA metabarcoding to unravel plant species composition in selected herbal medicines on the National List of Essential Medicines (NLEM) of Thailand

Traditional medicines are widely traded across the globe and have received considerable attention in the recent past, with expectations of heightened demand in the future. However, there are increasing global concerns over admixture, which can affect the quality, safety, and efficacy of herbal medicinal products. In this study, we aimed to use DNA metabarcoding to identify 39 Thai herbal products on the Thai National List of Essential Medicines (NLEM) and assess species composition and admixture. Among the products, 24 samples were in-house-prepared formulations, and 15 samples were registered formulations. In our study, DNA metabarcoding analysis using ITS2 and rbcL barcode regions were employed to identify herbal ingredients mentioned in the products. The nuclear region, ITS2, was able to identify herbal ingredients in the products at the genus- and family-levels in 55% and 63% of cases, respectively. The chloroplast gene, rbcL, enabled genus- and family-level identifications in 58% and 73% of cases, respectively. In addition, plant species were detected in larger numbers (Family identified, absolute %) in registered herbal products than in in-house-prepared formulations. The level of fidelity increases concerns about the reliability of the products. This study highlights that DNA metabarcoding is a useful analytical tool when combined with advanced chemical techniques for the identification of plant species in highly processed, multi-ingredient herbal products.

An Integrated Approach for Efficient and Accurate Medicinal Cuscutae Semen Identification

To guarantee the safety and efficacy of herbal medicines, accurate identification and quality evaluation are crucial. The ripe dried seeds of Cuscuta australis R.Br. and C. chinensis Lam. are known as Cuscutae Semen (CS) and are widely consumed in Northeast Asia; however, the seeds of other species can be misidentified as CS owing to morphological similarities, leading to misuse. In this report, we propose a multilateral strategy combining microscopic techniques with statistical analysis and DNA barcoding using a genus-specific primer to facilitate the identification and authentication of CS. Morphology-based identification using microscopy revealed that the useful diagnostic characteristics included general shape, embryo exudation, hairiness, and testa ornamentation, which were used to develop an effective identification key. In addition, we conducted DNA barcoding-based identification to ensure accurate authentication. A novel DNA barcode primer was produced from the chloroplast rbcL gene by comparative analysis using Cuscuta chloroplast genome sequences, which allowed four Cuscuta species and adulterants to be discriminated completely. Therefore, this investigation overcame the limitations of universal DNA barcodes for Cuscuta species with high variability. We believe that this integrated approach will enable CS to be differentiated from other species, thereby improving its quality control and product safety in medicinal markets.

Combined Liquid Chromatography-mass Spectrometry and Next-generation DNA Sequencing Detection of Adulterants and Contaminants in Analgesic and Anti-inflammatory Herbal Medicines

INTRODUCTION

Methods for assessing the quality of herbal medicine preparations have advanced significantly in recent years in conjunction with increases in herbal medicine use and reports of adulteration and contamination.

OBJECTIVE

This study examined the quality of analgesic and anti-inflammatory herbal medicine preparations available on the Australian market by detecting the presence of listed ingredients, adulterants and contaminants.

METHODS

Forty-nine analgesic and anti-inflammatory herbal medicine preparations were randomly sourced from Australian capital cities. They were audited using a dual approach of liquid chromatography-mass spectrometry (LC-MS) combined with next-generation DNA sequencing. Once screened, a comparison of listed ingredients with verified ingredients was conducted to determine the accuracy of labelling, and the extent of adulteration and contamination.

RESULTS

Twenty-six of 49 (53%) herbal medicines were adulterated or contaminated with undeclared ingredients. LC-MS revealed the presence of pharmaceutical adulterants including atropine and ephedrine. DNA sequencing uncovered concerning levels of herbal substitution, adulteration and contamination, including the use of fillers (alfalfa, wheat and soy), as well as pharmacologically relevant species (Centella asiatica, Panax ginseng, Bupleurum and Passiflora). Pig/boar and bird DNA was found in some preparations, inferring substandard manufacturing practices. Of the 26 contaminated samples, 19 (73%) were manufactured in Australia, and 7 (27%) were imported from other countries (6 from China, 1 from New Zealand). In 23 of 49 (47%) herbal medicine samples, no biological ingredients were detected at all. These were predominantly pain and anti-inflammatory preparations such as glucosamine and eicosapentaenoic and docosahexaenoic acids found in krill and fish oils, so DNA would not be expected to survive the manufacturing process.

CONCLUSION

The high level of contamination and substitution of herbal medicine preparations sourced from Australian dispensaries supports the need for more stringent pharmacovigilance measures in Australia and abroad.

Designing and construction of genetically encoded FRET-based nanosensor for qualitative analysis of digoxin

Nanobiotechnological improvements defined on the utilization of biological materials and principles have enormously partaken to revolutionize physical, chemical, and biological sciences. However, the exploration of plant nanobiotechnology is still in its outset. The search for novel tools to monitor plant biomolecules is an emerging issue for the nanobiotechnologists. Given this, a genetically encoded FRET-based nanobiosensor has been developed to monitor the popular plant cardiac glycoside - digoxin, which is used as the most common prescription drug for heart-related illnesses across the world. Digoxin is sourced from the leaves of the foxglove plant (Digitalis purpurea L.) and has a significant demand in the medical sector. Moreover, with the rising popularity of the herbal formulations in the global market, attention towards the authentication and quality control of the herbal drugs is important. Furthermore, digoxin has a very narrow therapeutic range, i.e., 0.6 nM - 2.6 nM. Therefore, strict monitoring of blood digoxin levels is necessary. Besides, previously used techniques for drug authentication and quantification of small-molecule drugs in blood samples are not the best choice available. The nanobiosensor is based on the FRET (Fluorescence Resonance Energy Transfer) mechanism, and it is constructed in such a way that it gives a changed FRET output in the presence of digoxin. Two fluorophores, enhanced cyan fluorescent protein (ECFP) and Venus, were attached on either end of the sensory domain - human nuclear receptor ROR-gamma (RORγt). The developed nanobiosensor was named as fluorescent indicator protein for digoxin, (FLIP-digoxin). The ligand binding affinity of FLIP-digoxin was calculated as 425 μM. Affinity mutants of the FLIP-digoxin were also generated to measure digoxin in wide concentration ranges. This sensor offers high-throughput qualitative analysis of digoxin in Digitalis preparations procured from local drug stores. It confirms the authenticity of the preparations through the detection of digoxin. The FLIP-1n was also able to monitor digoxin concentration in serum samples in lesser than 5 min. The nanobiosensor was found pH stable, digoxin-specific, non- interfered by the biological serum species and can perform high throughput screening of the Digitalis powder, infusion and tincture preparations.

Applied Barcoding: The Practicalities of DNA Testing for Herbals

DNA barcoding is a widely accepted technique for the identification of plant materials, and its application to the authentication of commercial medicinal plants has attracted significant attention. The incorporation of DNA-based technologies into the quality testing protocols of international pharmacopoeias represents a step-change in status, requiring the establishment of standardized, reliable and reproducible methods. The process by which this can be achieved for any herbal medicine is described, using Hypericum perforatum L. (St John's Wort) and potential adulterant Hypericum species as a case study. A range of practical issues are considered including quality control of DNA sequences from public repositories and the construction of individual curated databases, choice of DNA barcode region(s) and the identification of informative polymorphic nucleotide sequences. A decision tree informs the structure of the manuscript and provides a template to guide the development of future DNA barcode tests for herbals.

Comparative Plastomics of Ashwagandha (Withania, Solanaceae) and Identification of Mutational Hotspots for Barcoding Medicinal Plants

Within the family Solanaceae, Withania is a small genus belonging to the Solanoideae subfamily. Here, we report the de novo assembled chloroplast genome sequences of W. coagulans, W. adpressa, and W. riebeckii. The length of these genomes ranged from 154,162 to 154,364 base pairs (bp). These genomes contained a pair of inverted repeats (IRa and IRb) ranging from 25,029 to 25,071 bp that were separated by a large single-copy (LSC) region of 85,635-85,765 bp and a small single-copy (SSC) region of 18,457-18,469 bp. We analyzed the structural organization, gene content and order, guanine-cytosine content, codon usage, RNA-editing sites, microsatellites, oligonucleotide and tandem repeats, and substitutions of Withania plastomes, which revealed high similarities among the species. Comparative analysis among the Withania species also highlighted 10 divergent hotspots that could potentially be used for molecular marker development, phylogenetic analysis, and species identification. Furthermore, our analyses showed that even three mutational hotspots (rps4-trnT, trnM-atpE, and rps15) were sufficient to discriminate the Withania species included in current study.

Microscopic Authentication of Commercial Herbal Products in the Globalized Market: Potential and Limitations

Herbal products are marketed and used around the globe for their claimed or expected health benefits, but their increasing demand has resulted in a proportionally increase of their accidental contamination or intentional adulteration, as already confirmed with DNA-based methods. Microscopy is a traditional pharmacopoeial method used for plant identification and we systematically searched for peer-reviewed publications to document its potential and limitations to authenticate herbal medicines and food supplements commercially available on the global market. The overall authenticity of 508 microscopically authenticated herbal products, sold in 13 countries, was 59%, while the rest of 41% were found to be adulterated. This problem was extending over all continents. At the national level, there were conspicuous differences, even between neighboring countries. These microscopically authenticated commercial herbal products confirm that different magnifying instruments can be used to authenticate crude or processed herbal products traded in the global marketplace. The reviewed publications report the successful use of different magnifying instruments, single or in combinations with a second one, with or without a chemical or DNA-based technique. Microscopy is therefore a rapid and cost-efficient method, and can cope with mixtures and impurities. However, it has limited applicability for highly processed samples. Microscopic authentication of commercial herbal products will therefore contribute to raise public awareness for the extent of adulteration and the need to safeguard consumer safety against the challenges of globalization.

Detection and quantification of cashew in commercial tea products using High Resolution Melting (HRM) analysis

Tea, a popular aromatic infusion and food supplement, prepared from Camellia sinensis (L.) Kuntze leaves, is often subjected to adulteration with various undeclared inorganic and plant-derived materials. Cashew (Anacardium occidentale L.) nut husk is one of the most common plant tea adulterants. To date, there are limited DNA-based technologies for tea authentication and quantitative detection of adulterants. Herein, we used a universal plant DNA barcoding marker coupled with High Resolution Melting (Bar-HRM) analysis to authenticate tea products from cashew ground nut. Additionally, cashew-specific markers coupled with HRM technology were used to detect and quantify adulteration of tea with cashew DNA. This methodology can reliably detect admixtures as low as 1% v/v cashew in commercial tea products. Overall, our results demonstrate that the HRM technology is a strong molecular approach in tea authentication, capable of detecting very low adulterations in DNA admixtures. PRACTICAL APPLICATION: In this study, we established the use of high-resolution DNA-based technologies for the detection of cashew adulteration in tea, even in very low quantities. The technology could be applied to a greater range of plant-based tea adulterants. This work is expected to facilitate the traceability and authenticity of tea products and form the basis for the development of strategies against fraudulent practices.

Turning Meadow Weeds Into Valuable Species for the Romanian Ethnomedicine While Complying With the Environmentally Friendly Farming Requirements of the European Union's Common Agricultural Policy

The cross-compliance mechanism of the European Union (EU)'s common agricultural policy (CAP) makes the approval of the direct payments to the European farmers subject to compliance with the requirement to maintain the land in good agricultural and environmental condition. One of the obligations of the Romanian land owners and farmers is to avoid the installation of unwanted vegetation on their land plots. This vegetation is represented by some species of herbaceous or woody plants, annual or perennial, that spontaneously invade the agricultural lands, diminishing the production capacity of the cultivated plants. Included in this category are 10 meadow weeds, without fodder value or even toxic to animals: Arctium lappa L., Carduus nutans L., Conium maculatum L., Eryngium campestre L., Euphorbia cyparissias L., Pteridium aquilinum (L.) Kuhn, Rumex acetosella L., Veratrum album L., Xanthium spinosum L., and Xanthium strumarium L. Various and multiple uses in traditional medicine of these meadow weed species have been reported for Romania and other nine neighboring East European countries, i.e. Bosnia and Herzegovina, Bulgaria, Czech Republic, Estonia, Kosovo, Russia, Turkey, Serbia, and Ukraine. For A. lappa were recorded the highest number of ethnomedicinal uses, in the largest number of East European countries, including Romania. C. maculatum and V. album are not recommended for human consumption but can be further investigated as potential sources of pharmaceutically active compounds. Once removed by landowners and farmers from their land, the raw plant material of these 10 species become readily and easily available to the Romanian local communities and the industry of herbal food supplements, while the biodiversity of the agro-ecosystems is maintained.

Molecular Verification of the UK National Collection of Cultivated Liriope and Ophiopogon Plants

A collection of cultivated Liriope and Ophiopogon plants was established in 1996-1998 and subsequently hosted at a horticultural college. Uncertainties about the identification of the accessions, compounded by potential errors in propagation and labelling have led to waning confidence in the identities of the plants in the collection. The potential for using DNA barcoding to determine the species identities of the accessions was investigated. The DNA barcode regions of the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) and nuclear ribosomal internal transcribed spacer (nrITS) were amplified. DNA sequence analysis allowed the sequences of the accessions to be compared to reference sequences in public databases. A simple haplotype map of the characteristic polymorphic positions in the rbcL regions was used to clearly distinguish between the two genera and assign Ophiopogon accessions to individual species or sub-groups of species. The ITS sequence data confirmed these genus and species assignations and provided greater resolution to distinguish between closely related species. The combination of two DNA barcodes allowed most of the accessions to be assigned to individual species. This molecular verification confirmed the identity of about 70% of the accessions, with the remaining 30% demonstrating a range of mistaken identities at the species and genus levels.

A strategy for test article selection and phytochemical characterization of Echinacea purpurea extract for safety testing

Botanical dietary supplements (BDS) are used around the world for many purported therapeutic properties. The selection of an authentic product and it's phytochemical characterization is critical to generate robust safety data. Because botanicals are complex mixtures with variable quality, identification of a representative product for testing has been challenging. Echinacea is used for its purported immune stimulant properties and was listed as the 2nd top-selling BDS in 2018. However, there are limited safety data for Echinacea. Hence, the National Toxicology Program (NTP) has selected Echinacea for safety testing using rodent models. Here, we describe selection and comprehensive characterization of an Echinacea purpurea root extract to be used in the NTP testing program. Using non-targeted chemical analyses combined with chemometric analysis, a potential unfinished product (i.e., an extract that serves as source material for finished products) of Echinacea purpurea was selected. The product was then authenticated using chemical and DNA techniques and characterized, including the phytochemical composition. Among numerous constituents identified, caftaric acid, chicoric acid, chlorogenic acid and dodeca-2(E),4(E),8(Z),10(E/Z)-tetraenoic acid isobutylamide made up a small fraction of the extract. Based on these analyses, an approach is proposed for test article selection for Echinacea research which can be adapted to other botanicals.

Mitigating the Impact of Admixtures in Thai Herbal Products

Medicinal plants and their products are extensively used within indigenous healthcare systems in Thailand and several other nations. The international trade of herbal products has a noteworthy impact on the worldwide economy, and the interest in herbal products is expanding in both developing and developed countries. There has been rapid growth in the medicinal plant product market and a broadening consumer base interested in herbal products from Thailand. However, in herbal industries, ingredient substitution and admixture are typical issues wherein species of lower market value are admixed with those of a higher value. The adverse consequences of consuming adulterated drugs are invariably due to the presence of an unintended herb rather than the presence of an intended herb. It has also been argued that admixtures are intentional because of the lack of regulatory policies or centralized tests for product authentication. The consequences of species admixtures can extend from the reduced efficacy of a drug to decreased trade value. This study aims to clarify the nature and extent of species admixtures reported in the Thai herbal trade market and discuss the potential reasons for such adulteration. In the broader context of species admixtures, we strongly propose the establishment of multiple herbal crude drug repositories that can be developed to facilitate the use of comparative identity tests by industry, traders, and researchers to maintain authentic natural health product (NHP) standards and to certify the authenticity of NHPs. The proposition of the establishment of centralized testing (CT) could be a promising initiative in Thailand for the development of science and technology, and the herbal medicines produced as a result of CT could be dispensed as prescription drugs based on disease consideration instead of as health foods or nutraceuticals.

The DNA-Based Authentication of Commercial Herbal Products Reveals Their Globally Widespread Adulteration

The herbal products, sold worldwide as medicines or foods, are perceived as low risk because they are considered natural and thus safe. The quality of these products is ineffectively regulated and controlled. The growing evidence for their lack of authenticity is causing deep concern, but the scale of this phenomenon at the global, continental or national scale remains unknown. We analyzed data reporting the authenticity, as detected with DNA-based methods, of 5,957 commercial herbal products sold in 37 countries, distributed in all six inhabited continents. Our global survey shows that a substantial proportion (27%) of the herbal products commercialized in the global marketplace is adulterated when their content was tested against their labeled, claimed ingredient species. The adulterated herbal products are distributed across all continents and regions. The proportion of adulterated products varies significantly among continents, being highest in Australia (79%), South America (67%), lower in Europe (47%), North America (33%), Africa (27%) and the lowest in Asia (23%). The commercial HPs' authenticity among the 37 countries included in our global analysis ranges between 0 and 100% from the total number of product reported for each specific national marketplace. For 9 countries, more than 100 products were successfully DNA-based authenticated and reported. From these countries, the highest percentage of adulterated commercial HPs was reported for Brazil (68%), followed distantly by Taiwan (32%), India (31%), USA (29%), followed closely by Malaysia (24%), Japan (23%), South Korea (23%), Thailand (20%), and China (19%). Our results confirm the large-scale presence of adulterated herbal products throughout the global market. The adulterated herbal products contain undeclared contaminant, substitute, and filler species, or none of the labeled species, which all may be accidental or intentional, economically-motivated and fraudulent. Due to the ever-increasing analytical sensitivity of the high throughput DNA sequencing, increasingly used for the untargeted, simultaneous multi-taxa identification, the proportion of adulterated HPs detected on the global market is expected to increase. In the context of the increasing demand for HPs, the limited supply of raw materials derived from many plant species, some of which being already nationally or internationally protected and having various degrees of trade restrictions, adds up to the differences and discrepancies between national HPs' regulatory frameworks and further increases the risks of adulteration of many types of herbal products. The globally widespread adulteration is a serious threat to consumers' well-being and safety, in spite of herbal products' claimed or expected health benefits.

Chemical Barcoding: A Nuclear-Magnetic-Resonance-Based Approach To Ensure the Quality and Safety of Natural Ingredients

One of the greatest challenges facing the functional food and natural health product (NHP) industries is sourcing high-quality, functional, natural ingredients for their finished products. Unfortunately, the lack of ingredient standards, modernized analytical methodologies, and industry oversight creates the potential for low quality and, in some cases, deliberate adulteration of ingredients. By exploring a diverse library of NHPs provided by the independent certification organization ISURA, we demonstrated that nuclear magnetic resonance (NMR) spectroscopy provides an innovative solution to authenticate botanicals and warrant the quality and safety of processed foods and manufactured functional ingredients. Two-dimensional NMR experiments were shown to be a robust and reproducible approach to capture the content of complex chemical mixtures, while a binary normalization step allows for emphasizing the chemical diversity in each sample, and unsupervised statistical methodologies provide key advantages to classify, authenticate, and highlight the potential presence of additives and adulterants.

Forensic botany and forensic chemistry working together: application of plant DNA barcoding as a complement to forensic chemistry-a case study in Brazil

Recently, Brazilian Federal Police used forensic chemistry and forensic botany techniques on a case. Two packets containing fragmented plant matter were seized and sent for forensic analysis. Forensic chemistry, the gold standard for evaluating plant material suspected to contain illicit substances, did not find illicit materials. Gas chromatography coupled mass spectrometry (GC-MS) identified thujone in the botanical material. Thujone is a chemical compound naturally found in many plant species, notably Artemisia absinthium. Because doubt remained, we next used plant DNA barcoding methods. Total DNA from plant tissue fragments was extracted and five different DNA regions were amplified, sequenced, and analyzed using plant DNA barcoding methods. Genetic analysis yielded 30 good quality sequences representing five taxa. Most specimens were identified as A. absinthium. Few studies focus on practical forensic applications of plant DNA barcoding methods using a case solved in a forensic laboratory with its difficulties and limitations. To the best of our knowledge, this is the first study to report an effective joint effort of forensic chemistry and botany techniques to assess plant material in Brazil. The availability of a new technical approach for the genetic sequencing of plant species will enhance many forensic investigations and inspire similar initiatives.

DNA Authentication of St John's Wort (Hypericum perforatum L.) Commercial Products Targeting the ITS Region

There is considerable potential for the use of DNA barcoding methods to authenticate raw medicinal plant materials, but their application to testing commercial products has been controversial. A simple PCR test targeting species-specific sequences within the nuclear ribosomal internal transcribed spacer (ITS) region was adapted to screen commercial products for the presence of Hypericum perforatum L. material. DNA differing widely in amount and extent of fragmentation was detected in a number of product types. Two assays were designed to further analyse this DNA using a curated database of selected Hypericum ITS sequences: A qPCR assay based on a species-specific primer pair spanning the ITS1 and ITS2 regions, using synthetic DNA reference standards for DNA quantitation and a Next Generation Sequencing (NGS) assay separately targeting the ITS1 and ITS2 regions. The ability of the assays to detect H. perforatum DNA sequences in processed medicines was investigated. Out of twenty different matrices tested, both assays detected H. perforatum DNA in five samples with more than 10³ ITS copies µL⁻¹ DNA extract, whilst the qPCR assay was also able to detect lower levels of DNA in two further samples. The NGS assay confirmed that H. perforatum was the major species in all five positive samples, though trace contaminants were also detected.

Food Tracking Perspective: DNA Metabarcoding to Identify Plant Composition in Complex and Processed Food Products

One of the main goals of the quality control evaluation is to identify contaminants in raw material, or contamination after a food is processed and before it is placed on the market. During the treatment processes, contamination, both accidental and economically motivated, can generate incongruence between declared and real composition. In our study, we evaluated if DNA metabarcoding is a suitable tool for unveiling the composition of processed food, when it contains small trace amounts. We tested this method on different types of commercial plant products by using tnrL marker and we applied amplicon-based high-throughput sequencing techniques to identify plant components in different food products. Our results showed that DNA metabarcoding can be an effective approach for food traceability in different type of processed food. Indeed, the vast majority of our samples, we identified the species composition as the labels reported. Although some critical issues still exist, mostly deriving from the starting composition (i.e., variable complexity in taxa composition) of the sample itself and the different processing level (i.e., high or low DNA degradation), our data confirmed the potential of the DNA metabarcoding approach also in quantitative analyses for food composition quality control.

Employing barcoding markers to authenticate selected endangered medicinal plants traded in Indian markets

The high demand of medicinal plants and their unrestricted collection have rendered many of these as rare or endangered. The restrictions imposed on their collection and trade are difficult to implement because of the inability to identify them in fragmented form. The rarity of these plants in nature and lack of their cultivation raise doubt about the authenticity of the herbals sold in markets. Therefore, in the present investigation, ITS/ITS2, matK, rbcL and rpoC1 sequences of fourteen species of important medicinal plants, some of which are endangered, were generated and checked for their species-specificity (sequences having maximum similarity only with their own) by BLAST1 and/or BOLD identifications. ITS sequences of 12 species were species-specific. However, ITS2 of only 10 of these 12 species were species-specific. As for the chloroplast loci, rbcL and rpoC1 sequences of all 14 species could be obtained, while matK sequences of only 10 of these could be generated. Of the retrieved sequences, rbcL, rpoC1 and matK sequences of 7, 11 and 7 species, respectively, were species-specific. The sequences of the targeted loci from the herbal samples of these species were difficult to retrieve because of failure in the amplification or sequencing. Nevertheless, based on ITS2 and/or one or more of the chloroplast loci targeted, the botanical identities of 22 herbal market samples were checked by phylogenetic tree, BLAST1 and BOLD identification methods. Of these 22 samples, only one of each of Rauvolfia serpentina and Picrorhiza kurroa were found to be authentic.

DNA Metabarcoding Authentication of Ayurvedic Herbal Products on the European Market Raises Concerns of Quality and Fidelity

Ayurveda is one of the oldest systems of medicine in the world, but the growing commercial interest in Ayurveda based products has increased the incentive for adulteration and substitution within this herbal market. Fraudulent practices such as the use of undeclared fillers and use of other species of inferior quality is driven both by the increased as well as insufficient supply capacity of especially wild plant species. Developing novel strategies to exhaustively assess and monitor both the quality of raw materials and final marketed herbal products is a challenge in herbal pharmacovigilance. Seventy-nine Ayurvedic herbal products sold as tablets, capsules, powders, and extracts were randomly purchased via e-commerce and pharmacies across Europe, and DNA metabarcoding was used to assess the ability of this method to authenticate these products. Our analysis reveals that only two out of 12 single ingredient products contained only one species as labeled, eight out of 27 multiple ingredient products contained none of the species listed on the label, and the remaining 19 products contained 1 to 5 of the species listed on the label along with many other species not specified on the label. The fidelity for single ingredient products was 67%, the overall ingredient fidelity for multi ingredient products was 21%, and for all products 24%. The low level of fidelity raises concerns about the reliability of the products, and detection of threatened species raises further concerns about illegal plant trade. The study highlights the necessity for quality control of the marketed herbal products and shows that DNA metabarcoding is an effective analytical approach to authenticate complex multi ingredient herbal products. However, effort needs to be done to standardize the protocols for DNA metabarcoding before this approach can be implemented as routine analytical approaches for plant identification, and approved for use in regulated procedures.

DNA Mini-Barcoding: A Derived Barcoding Method for Herbal Molecular Identification

In recent years, the demand for natural herbal products (NHP) has increased; however, the quality of these products is difficult to confirm due to the lack of a comprehensive quality control system. Traditional methods are not effective in detecting processed ingredients. DNA barcoding is an established technique that has been used for more than 10 years. This technique uses short standard sequences (generally 200-600 bp) to identify species. While a complete DNA barcode is difficult to obtain from NHP due to DNA degradation, mini-barcoding is a complementary tool to identify species in NHP. DNA mini-barcoding uses smaller DNA segments for polymerase chain reaction amplification and can be applied to identify species rapidly. The present review summarizes the development and application of DNA mini-barcodes over recent years and discusses the limitations of this technique. This review also compares mini-barcoding and meta-barcoding, a technique using universal polymerase chain reaction primers to simultaneously amplify multiple DNA barcodes and identify many species in a single environmental sample. Additionally, other detection methods that can be combined with mini-barcodes, such as nucleotide signatures, high-resolution DNA melting analysis, and gold nanoparticles, are discussed. DNA mini-barcoding can fill the gaps left by other methods in the field of herbal molecular identification.

Sequence-Specific Detection of Aristolochia DNA - A Simple Test for Contamination of Herbal Products

Herbal medicines are used globally for their health benefits as an alternative therapy method to modern medicines. The market for herbal products has increased rapidly over the last few decades, but this has in turn increased the opportunities for malpractices such as contamination or substitution of products with alternative plant species. In the 1990s, a series of severe renal disease cases were reported in Belgium associated with weight loss treatment, in which the active species Stephania tetrandra was found to be substituted with Aristolochia fangchi. A. fangchi contains toxic aristolochic acids, which have been linked to kidney failure, as well as cancers of the urinary tract. Because of these known toxicities, herbal medicines containing these compounds, or potentially contaminated by these plants, have been restricted or banned in some countries, but they are still available via the internet and in alternate formulations. In this study, a DNA based method based on quantitative real-time PCR (qPCR) was tested to detect and distinguish Aristolochia subg. Siphisia (Duch.) O.C.Schmidt species from a range of medicinal plants that could potentially be contaminated with Aristolochia material. Specific primers were designed to confirm that Aristolochia subg. Siphisia can be detected, even in small amounts, if it is present in the products, fulfilling the aim of offering a simple, cheaper and faster solution than the chemical methods. A synthetic gBlock template containing the primer sequences was used as a reference standard to calibrate the qPCR assay and to estimate the copy number of a target gene per sample. Generic primers covering the conserved 5.8S rRNA coding region were used as internal control to verify DNA quality and also as a reference gene for relative quantitation. To cope with potentially degraded DNA, all qPCR primer sets were designed to generate PCR products of under 100 bp allowing detection and quantification of A. fangchi gBlock even when mixed with S. tetrandra gBlock in different ratios. All proportions of Aristolochia, from 100 to 2%, were detected. Using standards, associating the copy number to each start quantity, the detection limit was calculated and set to about 50 copies.

Trade in Zambian Edible Orchids-DNA Barcoding Reveals the Use of Unexpected Orchid Taxa for Chikanda

In Zambia, wild edible terrestrial orchids are used to produce a local delicacy called chikanda, which has become increasingly popular throughout the country. Commercialization puts orchid populations in Zambia and neighbouring countries at risk of overharvesting. Hitherto, no study has documented which orchid species are traded on local markets, as orchid tubers are difficult to identify morphologically. In this study, the core land-plant DNA barcoding markers rbcL and matK were used in combination with nrITS to determine which species were sold in Zambian markets. Eighty-two interviews were conducted to determine harvesting areas, as well as possible sustainability concerns. By using nrITS DNA barcoding, a total of 16 orchid species in six different genera could be identified. Both rbcL and matK proved suitable to identify the tubers up to the genus or family level. Disa robusta, Platycoryne crocea and Satyrium buchananii were identified most frequently and three previously undocumented species were encountered on the market. Few orchid species are currently listed on the global International Union for the Conservation of Nature (IUCN) Red List. Local orchid populations and endemic species could be at risk of overharvesting due to the intensive and indiscriminate harvesting of chikanda orchids, and we therefore encourage increased conservation assessment of terrestrial African orchids.

DNA barcoding of species of Bacopa coupled with high-resolution melting analysis

In Thailand, there are three species of Bacopa, namely, B. monnieri, B. caroliniana, and B. floribunda. Among these species of Bacopa, B. monnieri is the only medicinal species, used for the treatment of cognitive impairment and improvement of cognitive abilities because of its bioactive constituents, bacoside A and B. However, because of the similar characteristics of these species, it is difficult to differentiate among related species, resulting in confusion during identification. For this reason, and to ensure therapeutic quality for consumers, authentication is important. In this study, the three abovementioned species of Bacopa were evaluated using barcoding coupled with high-resolution melting (Bar-HRM) analysis based on primers designed for the trnL-F sequences of the three species. The melting profiles of the trnL-F amplicons of B. caroliniana and B. floribunda were clearly different from the melting profile of the trnL-F amplicon from B. monnieri; thus, the species could be discriminated by Bar-HRM analysis. Bar-HRM was then used to authenticate commercial products in various forms. The melting curves of the six commercial samples indicated that all the tested products contained genuine B. monnieri species. This method provides an efficient and reliable authentication system for future commercial herbal products and offers a reference system for quality control.

Precise species detection of traditional Chinese patent medicine by shotgun metagenomic sequencing

BACKGROUND

Current quality control methods for traditional Chinese patent medicines (TCPMs), e.g., microscopy, thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC), cannot detect herbal species composition with adequate precision. To address this issue, more effective detection methods should be explored.

HYPOTHESIS/PURPOSE

We hypothesized that shotgun metagenomic sequencing can fulfill the requirements for the species detection of multi-ingredient TCPMs.

METHODS

Longdan Xiegan Wan (LDXGW), once thought to be the chief culprit in aristolochic acid nephropathy (AAN), was selected to establish the method. It was used for both reference and commercial LDXGW samples. The precision authentication of herbal species contained in multi-ingredient TCPM is based on the shotgun metagenomic sequencing of genomic DNA without PCR amplification. Chemical analyses were also conducted as a contrast test.

RESULTS

Over 100 G of raw data was obtained, and this value represented more than 0.75 billion reads. After assembling and filtering all the reads, a total of 261 contigs were obtained, which belonged to the ITS2, psbA-trnH, and matK regions of the reference and commercial samples. Because the homology of the rbcL region was high, it was not analyzed in the HTS data. Bioinformatics analysis indicated that the ITS2 region, as a DNA barcode, showed the highest identification efficiency. It could successfully detect all prescribed species, including four processed herbal ingredients, in the lab-made reference samples. The commercial samples all met the requirements of the Chinese Pharmacopoeia according to the TLC and HPLC tests. However, the shotgun metagenomic sequencing detected the substitution of Akebiae Caulis (Mutong) in the commercial samples, while the chemical analyses could not distinguish.

CONCLUSION

The results highlight that shotgun metagenomic sequencing is a complementary method for the precise species detection of TCPMs.

DNA barcoding to promote social awareness and identity of neglected, underutilized plant species having valuable nutritional properties

It is estimated that about 7000 plant species and a large number of cultivars and varieties have been cultivated for consumption in human history. However, <0.5% of these currently provide the majority of human food energy needs worldwide (e.g., rice, wheat, maize, and potato). Global issues such as climate change, diffusion of pests, and resistance to agrochemical treatments are posing great concern about the sustainable cultivation of these major staples, especially in equatorial and tropical countries, such as Sub Saharan Africa. In addition, most of these regions contain malnutrition and micronutrient deficiencies, and the sum of such problems create serious implications at social, political, and economic levels. A possible solution relies on the exploitation of plant biodiversity and particularly on the so-called NUS (Neglected and Underutilized Species). These plants are traditionally grown in their centres of origin and continue to be maintained by sociocultural preferences, however they remain inadequately documented and neglected by formal research and conservation programs. Although they are important in terms of micronutrients and the ability to grow in harsh conditions, these species are falling into disuse due to agronomic, genetic, economic, and cultural reasons. To promote and spread their cultivation at the global scale, along with knowledge on their suitability for human nutrition, reliable identification systems are necessary to guarantee adequate authenticity along the entire supply chain and distribution network. A precise identification of the different species and their varieties is fundamental both to retrieve information on their origin and authenticate the raw materials (i.e., seeds, leaves and fruit) and related processed products that can be distributed at the local or global scale. DNA-based techniques can help achieve this mission. In particular, the DNA barcoding approach has gained a role of primary importance due to its universality and versatility. Here, we discuss the advantages in using DNA barcoding for the identification of some of the most representative NUS species, as well as their traceability and conservation of cultural practices around them.

Molecular Markers Associated With Chemical Analysis: A Powerful Tool for Quality Control Assessment of Copalchi Medicinal Plant Complex

The copalchi complex, Hintonia latiflora, H. standleyana, and Exostema caribaeum, is widely used in Mexico for treating diabetes and gastrointestinal disorders. The first therapeutic use for H. latiflora bark was registered in the "Florentine Codex" in the sixteenth century. The latest pharmacological and phytochemical studies revealed that the infusion of the leaves have hypoglycemic, antihyperglycemic and gastroprotective activities. For these reasons the monograph of the main copalchi species, H. latiflora, was recently added to the Mexican Herbal Pharmacopoeia. Nevertheless, quality control parameters are focused to the bark but not to the leaves. Moreover, information about other Rubiaceae species is needed. The main goal of this study was to generate molecular and chemical markers for quality control of the copalchi complex raw material. In addition, the resolution of the taxonomical ambiguity between H. latiflora and H. standleyana, as well as the testing of the molecular and chemical markers in different geographical batches, were aims of this study. The molecular markers and chemical profiles of the leaf infusions were generated considering three different populations for H. latiflora and separate individuals of the three species (HL, n = 10; HS, n = 3; EC, n = 4). The molecular markers matK, rbcL, trnH-psbA, rpl32-trnL, and ITS2 were tested for their discriminating capabilities. Chemical profiles of the leaf infusions were obtained by means of HPLC analyses using chlorogenic acid and 4-phenylcoumarins as chemical markers. The concatenated sequence of the molecular markers trnH-psbA, rpl32-trnL, and ITS2 clearly distinguished the three taxa, clarifying the taxonomical ambiguity of the Hintonia genus. Additionally, the chemical profiles allowed the unequivocal identification of each species supporting the molecular results; the geographical origin of the samples did not modify neither the chemical profiles nor the concatenated sequence of H. latiflora, suggesting that it is a robust identity test. The complementary use of molecular and chemical markers will assure the quality of plant material used in traditional medicine for therapeutic purposes, and should be valuable new information for the National Health authorities as a part of the Mexican Herbal Pharmacopoeia.

DNA Barcoding for the Identification and Authentication of Animal Species in Traditional Medicine

Animal-based traditional medicine not only plays a significant role in therapeutic practices worldwide but also provides a potential compound library for drug discovery. However, persistent hunting and illegal trade markedly threaten numerous medicinal animal species, and increasing demand further provokes the emergence of various adulterants. As the conventional methods are difficult and time-consuming to detect processed products or identify animal species with similar morphology, developing novel authentication methods for animal-based traditional medicine represents an urgent need. During the last decade, DNA barcoding offers an accurate and efficient strategy that can identify existing species and discover unknown species via analysis of sequence variation in a standardized region of DNA. Recent studies have shown that DNA barcoding as well as minibarcoding and metabarcoding is capable of identifying animal species and discriminating the authentics from the adulterants in various types of traditional medicines, including raw materials, processed products, and complex preparations. These techniques can also be used to detect the unlabelled and threatened animal species in traditional medicine. Here, we review the recent progress of DNA barcoding for the identification and authentication of animal species used in traditional medicine, which provides a reference for quality control and trade supervision of animal-based traditional medicine.